Method of and apparatus for relieving wire circuits of electrostatic reaction-currents.



N. G. WARTH. METHOD OF AND APPARATUS FOR RELIEVING WIRE CIRCUITS OF ELECTROSTATIC REACTION OURRENTS.

APPLICATION FILED SEPT.16,1907.

Patented Nov. 17, 1908.

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wit-messes N. G. WARTH. METHOD OF AND APPARATUS FOR RELIEVING WIRE CIRCUITS 0F ELECTROSTATIC REACTION UURRENTS.

APPLIOATION FILED SEPT.16, 1907.

amvemtoz ay; Nathamemwarth ay/W25 QM QVA flatter/nu UNITED STATES PATENT OFFICE.

NATHANIEL G. WARTH, OF COLUMBUS, OHIO.

METHOD OF AND APPARATUS FOR RELIEVING WIRE CIRCUITS OF ELECTROSTATIC REACTION-OURRENTS.

Specification of Letters Patent.

Patented Nov. 17, 1908.

Application filed September 16, 1907. Serial No. 392,989.

To all whom it may concern:

Be it known that I, NATHANIEL G. WARTH, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented a certain new and useful Improvement in Methods of and Apparatus for Relieving Wire Circuits of Electrostatic Reaction-Currents, of which the following is a specification.

My invention appertains to the class or systems of electric transmission wherein high frequency electrical waves or varying electro-motive forces are produced at a generating or transmitting station, and are t-hereat impressed upon, or applied to, a connecting wire or other conducting medium, and transmitted to a distant receiving station.

The invention is directed particularly to the method of and the apparatus for overcoming the retarding and opposing electrical efl'ects due to electrostatic reacting cur-' rents in a conducting wire, which electrostatic currents are a product or result of the initial electro-magnetic or dynamic currents generated and applied to the circuit, and operate in a large degree through the electro-static constant of the circuit and in proportion thereto, to depreciate and degrade, both as to amplitude and form, the originating currents; these effects commonly being termed attenuation and distortion of the waves. By reducing the limitations to telephonic transmission caused by these electrostatic reaction currents, I not only facilitate and extend the efl'ective distance of transmission of' the fundamental speech waves but retain in such transmission a larger proportion than is usual of the accompanying harmonic or overtone waves.

In the methods heretofore proposed and largely adopted, as exemplified in the Pu in system of loading telephone and ot er circuits for high frequency transmission, it has been recognized that the electrostatic reaction is the factor, more than'either the leakage or resistance, that operates tolimit good transmissionoverlong distances, and

ollowing Oliver Heavisides theories and mathematical deductions, various methods, other than the Pupin loading method, have been pro osed or resorted to, to compensate for the e ectro-static reaction, and a number of patents have been issued for such inventions.

My invention consists more particularly in applying combined inductance and noninductance coils, termed herein composite coils, to the usual form or character of circuit or circuit conductors, the coils connecting the circuit with the earth, or a metallic return, at fixed or predetermined points, being wound or connected to serve as impedances to prevent any loss, through them or to the ground, of the originating currents, and also to serve as non-inductive or nonimpedance elements, to cause the exhaust or effect the dissipation of the electrostatic opposing currents.

The invention also consists, not only in the application of such type of coils to the circuit and in connecting them between the circuit and the earth, but in the particular distribution or application of the coils to the circuit throughout its length, and in the adjustment of the spacing distance between coils to various types of circuit.

The particular features of the invention, together with minor elements, will be fully understood by reference to the accompanying drawings, in connection with the following detailed description and specification.

In said drawingsFigure 1' diagrammatically illustrates merely a mechanical or acoustical analogy, to aid in the interpretation of the electrical conditions and actions involved in transmitting Waves through a circuit equipped with apparatus to operate according to my method. Fig. 2 is 9. diagrammatic illustration of a mechanical analogy of the theory of the action, as to the original currents, wherein a reed represents an inductance or retardation coil having a particular location on, or rather, a peculiar selective action between, the currents in a circuit. This illustration is to be considered in connection with Fi 1. Fig. 3 is a similar type of diagram illustrating the theory by means of a reed of the action involved in a noninductance coil by the electrostatic currents, whether they are electrostatic reactance or electrostatic induced currents, the coils to have a particular location and association alon or with the circuit. Fig. 4 diagrammatically represents a simple metallic circuit connecting a transmitting and a receiving station, the circuit being equipped with distributed composite or inductancenon-inductance coils, connected to the line wires and the ground, at definite intervals and in corresponding positions, for diverting llr the electrostatic currents in accordance with my invention. F ig. 5 represents diagrammatically a compound circuit, formed of sections of standard cable and open wire conductors, illustrating my method of combining such a circuit and the composite or inductance-non-inductance coils to secure a maximum efficiency circuit, according to my invention. Fig. 6 is a diagram representing a pair of cable conductors equipped with the composite coils, according to my invention, and illustrating their'application to a single or ground return circuit, and'also as a metallic circuit, the two circuits thus formed serving as a composite system, and adapted to operate as two distinct circuits. Fig. 7 is a diagrammatic representation of a smgle or ground return cable circuit, consisting of but one conductor equipped with the composite coils, but combining auxiliary features, to adapt the coils to the peculiar condition of a single grounded circuit. Fig. 8 diagrammatically represents one form or embodiment of the composite or retardative and non-inductance coil, for predetermined sectional distribution, applied to a circuit to create the electrostatic exhausting divisions, the coils in this arrangement being adapted to be highly impermeable to the initial or electro-magnetic waves or currents impressed upon the circuit, and highly permeable'to the electrostatic reaction currents set up in the conductors throughout the length of the circuit. Fig. 9 diagrammatically represents one embodimentof my inductance and phase-displacing coil in a single conductor circuit for association and cooperation with the composite line-coils, in accordance with my invention for securing maximum efiiciency in the transmission of electric undulations. Fig. 10 diagrammatically represents the preferred manner of connecting the composite line-coils to a metallic circuit, in association with protective devices to secure the coils and auxiliary apparatus from damage -by lightning and heavy or dangerous currents affecting open wire conductors, and also showing the use of condensers to provide for testing and measuring in connection with the maintenance of the circuits.

The transmission of electrical oscillations or waves having the frequency of speech vibrations and higher, through wire conductors, as is well known, is rendered very difficult by reason of the electrostatic or storing capacity of the circuit, and particularly by the restoring of a portion of such energy to the. circuit, causing electrostatic reaction utilized, and the distance separating the conductors or separating the single conductor from other conducting media. If the natural inductance factor of a circuit were of equivalent value to the electrostatic factor, they would normally counteract and nullify each other, as they are in opposition, and the circuit would in that event be naturally relieved of the electrostatic opposing effect. As such, however, is not the condition, the addition of inductance in sufiicient value. or quantity to neutralize the electrostatic effect in accordance with Pupins formula, has been resorted to by means of inductance or so-callecl loading coils, distributed along a circuit at predetermined points, or by means since suggested by others and myself, of combining copper and iron in a conductor in various ways, such, for instance, as covering an iron wire with a copper envelop, or the reverse, of covering a copper wire with -.an iron envelop, &c., throughout the conductors length.

As the electrostatic capacity of a circuit is an ever present, though, owing to environment, somewhat variable property of a conductor, it must be reckoned with; and as it necessarily creates for such transmission currents as are herein contemplated, the counter-currents mentioned, it has been my aim to devise and I have devised'means" whereby these counter-currents may, in a peculiar and beneficial manner, be withdrawn, in a; regulated manner, and practically entirely from the circuit, the original currents being thereby correspondingly facilitated and accelerated in their propagation. In explanation of the principles involved in accomplishing such transmission, reference will first be had to Fig. 1, wherein a tuning-fork l, or other vibrating tongue, or reed, controls the vibrations of a stretched flexible string 2, the fork and string representing analogously respectively a generator or transmitter and a conducting line. An initial Wave in the string propagated by the fork 1, at the end (A) of the string, is represented by the wave-line 3. Forks, or reeds, 4 and 5, representing analogously composite line-coils, are arranged along the string and by means of'connecting rods 4 and 5*, respectively, to vibrate with the string.

The fork 1 has a fundamental rate of vibration, and the Wave-line 3 represents graphically the length and amplitude of the vibrations. If the reed 4 be at,a common nodal-point from the fork, see 6, it will not be vibrated, or if it be located at a point where opposite waves meet or collide, an interference will result, and it will not vibrate. Hence, it consumes no energy in either case, but will consume energy when participating in a vibration, as at the fork, or reed 5. The absorption of energy by the fork and the dampening and decimation of the vibrations will be proportional to its vibrational resistance. The wave-line 8 represents a reflected or reacting wave, thrown back by the support or stop 7 at the opposite end of the string at B. Fig. 2 represents more clearly the first condition, as at reed 4, Fig. 1, assumed above, for a reed (4) located at a nodalpoint (6) to all Waves, or broadly, a point of no vibration. Fig. 3 represents clearly the second condition. as at reed "5, Fig. 1. assumed above. of a reed (5) so 1 ated that. it will be vibrated by all waves along the string.

Assuming that a number of the reeds (4) are properly distributed, as explained, along the string, it will be clear that the initial Waves in the string will be propagated vvithout being subjected to any decimation or distortion, and Without resistance, in so far as the reeds are concerned, and with only the resistance incident to the Weight of the string, the air friction and any other normal resistance factors present. Assuming that initial vibrations can also be caused at the opposite end B of the string, that the stop or support 7 is a fork, and that these vibrations are like those originated by the fork 1, at A, then the original vibrations from each end of the string Will be like those from the other, in their freedom from interfering action by the distributed reeds. Now, assuming that the initial vibrations produce reflected or counter-vibrations 8 from support 7, (which support serves in an analogous modified sense for the usual circuit dielectric) the conntervibrations or Waves 8 have a smaller amplitude, and are therefore more intense or of different periodicity than the initial waves. hence it will be apparent that the reeds. as indicated by reed 5, will be subjected to vibration, and. will cause, through its exhausting action, the reflected waves to be decimated and dissipated. While the above is but a mechanical or acoustical analogy of Wave propagation, the actions and functions of the parts of my invention agree very closely with those in the electrical system illustrated in Fig. 4. In said view the relative parts, their functions and the operations. are as follows: At the terminals A and 15' of the circuit, or conductors 2, 2 are transmitters and receivers l, 1", which may be telephonic instruments or otherwise, according to the character of the service. Assuming the service to be the transmission of speech, with its most complex of wave forms, coils 4 are distributed along the circuit and connected thereto, and to theground G, at distances regulated by the character of the circuit. particularly with regard to the electrostatic capacity of the circuit, the conditions governing the locations to be eX plained subsequently. These coils. instead of being located at points conforming to the assumed node and loop conditions along the 5 circuit. illustrated by the reeds l and 5. are

constructed to meet the analogous electrical condition. that is. they are wound and connected to the circuit to subserve the first state by high inductances. and to meet the second state by high permeability. The coils have a continuous winding, the two ends.c and c of which are connected to the circuit. in this instance. one, end to one line conductor and the other end to the. other line conductor. immediately opposite. tap connection 2 is made at the middle of each coil -lfor the connection with the ground. The winding or windings w and in on the coils are continuous or cooperative to currents flowing through them from line terminal to line terminal of each coil. and are thus higly retardative or impermeable to waves of a speech or higher frequency. and this is because the ohmic resistance is in series to such current flow, and to the counter electro-motive-force or core and coil reactions set up. Both conditions create maximum retarding and reaction effects. There is. of course. some inductance effect produced in the attenuft of the electro-magnetic initial currents to pass through the coils. but this is beneficial in aiding the initial currents. because any residual electro-static currents are neutralized. To the oscillating elcctro-static reactive currents that flow through the windings in parallel from the line wires to the ground, the ohmic resistance is divided. and as the currents flow differentially about the cores. no retardation or cotniter-electro-motive-forcecurrents are created. Hence. in this instance of use, the coils are highly permeable and offer a minimum resistance to the flow of the oscillating currents.

Assuming that a wave is transmitted from .terminal A Fig. 4. it will flow around the circuit, say outward in conductor '3 and back in conductor 2. The said circuit having no coils connected directly or serially therein, and with the bridging coils -l impermeable to the waves. the results obtained are that the circuit or the coinluctors arc in a state which may be termed uniform. and a circuit wherein the factors of ohmic re istance. mutual capacity and hunting resistance. or insulation. are all rcgulatablc. and

are the governing factors. The tran mission static currents set up in the circuit by the discharge of the electrostatic capacity charge with each variation or alternation in the initial current. The losses due to all but the last-mentioned cause are absolute, while the loss due to the latter cause has, in the Pupin system of added self-induction, been largely overcome.

The operation of my system, as, exemplified in Fig. 4, is as follows: A wave, as stated, emanating from the transmitter 1, at station A, and flowing around the metallic circuit 2, 2 will, as usual, lose a portion of its energy to the dielectric, but a portion of such energy, depending on the electrostatic factor of the circuit, will be immediately released and returned to the circuit and act as an opposing electrostatic current. This is graphically illustrated by the return wave 8 in Fig. 1. The initial wave will be prevented from spending or exhausting itself through the distributed coils 4 because they are unresponsive by reason of their inductance characteristic, just as though situated at a common zero potential point for all the initial waves, as explained in connection with reed 4 of Fig. '1. Assuming that these coils are distributed throughout the length of the circuit in an approximately uniform man'-' ner, they would be unable to respond to the original currents set 11 at either end of the line, and While the coil; are not of large inductance value or utility in this system, in connection with the transmission of the original currents, they are slightly beneficial and do not introduce any resistance whatever into the circuit.

As before suggested, the electrostatic reactive currents are set up by the reflex act-ion of the dielectric charge. Such reactive currents become active or dynamic in character in the circuit, and when permitted tofiow without means for opposing them, they tend to destroy the parent succeeding initial currents. The flow of these electrostatic reactive currents is similar to that of the initial currents and can be sectionally controlled along the circuit by the action of the coils 4 so that the currents set up in the successive sections of a line and intermediate the coils, will be exhausted through the nearest coils, due to their permeability or receptive conductivity to currents made to flow through their windings ditl'erentially. Thus the coils by reason of their cooperation, their resonance, and permeability, become active to participate in the movement or effect of the waves, and to readily absorb or exhaust them, as was the analogous case of reed 5 in Fig. 1, where the reed is adapted or functioned to participate in all the movements of the reflected waves in the string. the reflected waves in that instance being illustrative of the reactive electrostatic currents in this instance. The several current [lows are illustrated by the airrows, thus, the long solid arrows the initial currents, the short arrows the electrostatic reacting currents, and the broken line arrows the induced static or extraneous currents. As the initial current in this instance traverses the circuit from A to B through conductor 2 and returns through conductor 2' (shown by the long arrows), the electrostatic reaction currents (shown by the short arrows) fiow opposingly in the rectifying sections throughout the length of the circuit. The sectional flows change direction with each alternation of the initial current, and in each instance the flows to each coil are from both conductors but from alternate conductors in each of two sections.

The oscillations of the currents in each leg 'Each coil in this manner exhausts a half unit section, or one coil section, in each conductor on alternate legs of the circuit with each ways. A section of an extraneous conductor is illustrated at E, which may induce electrostatic currents into open wires (the wires being equidistant), as shown by the broken arrows. In such an event the coils Will deflect them from the telephone circuit in. both directions from an intermediate point in the two conductors simultaneously. At the ends A and B of the circuit the first rectified sections, or half sections, must exhaust their electrostatic reactive currents through the first coil or through a ground leg connected to the middle portion of the station re ating, or induction coil, as indicart-ed at fi and R This, however, is not important, as the quantity of power for counter effect in so short a section is very small and the coils will,'by reason of their inductance effects, if properly proportioned,

neutralize such an amount or effect of the electrostatic reaction. The rectifying or clearing effect of the coils or resistance vents, when applied to the circuit within the limiting distances contemplated in this invention render it possible to enlarge or extend somewhat the specific unit lengths or spacing distances along'a circuit without im pairing the transmission, but I prefer to limitthe unit lengths to the specific unrecti fied undistorting distances. To graphically define the locations or points of application of the coils to a circuit secure the desired results and yet to effect this economically, is the function of the apparatus illustrated in Fig. 5: In said diagram the circuit is represented as composed of both cable and open wire sections, the cable and 0 en wire portions being of different electrica proportions or values. Accepting the usual dry core paper insulated standard number 19 gage cable as a standard or basis for comparison with other types of lines, I have ascertained practically that transmission.

[through a pair of such wires is good and but very slightly impaired through a length of three miles. That is, this length of such cable circuit has been empirically ascertained to be the greatest for apparent undiminished or undistorted transmission. Adopting this length of standard cable as the unit for rectifica-tion lspace the coils accordingly. The spacing of coils on other cables may be readily computed by the same method. Thus, if a cable has a greater electrostatic capacity with the same ohmic resistance, the coils would be spaced closerl proportionately. Should a cable have the same capacity and less ohmic resistance, the coils would be spaced further apart proportionately. Or, where a cable has a conductor of larger cross section and therefore less resistance but larger electrostatic capacity, the spacing would remain practically the same as for v the given standard, because the electrostatic currents flow in the circuits serially, similarly to the dynamic or electro-magnetic, currents producing the differential effects in the coils are secured with each particular impulse from but one conductor of a rectit'ying section on each side of each opposite or corresponding coil, as shown by the arrows. It will be apparent that the distancefor spacing will be increased in proportion to the cross section of the conductor, modified by the electro-static capacity. In order that each coil may best exhaust its unit length of circuit section, it should be located substantially equidistant from the ends of the unit section that it for the instant serves, or where three-mile sections obtain as explained the coils can be 1?; miles apart. It will be understood that the action in the exhausting unit sections is progressive and excessive with the current flow through the successive sections. lVhen open wires are concerned, itwill be advisable to modify the spacing because of the variable electrical and electrostatic environments and degrees of exposures of such circuits to other circuits, and particularly their exposure .to parallel high power, high frequency circuits. Coils can be interposed, if desired, between the coils spaced as-described, but it is important that the spacing of the coils herein proposed should not exceed the unit distances for good transmission over the circuit with or without the coils added and consistently witlrthe form or frequency of wave.

In Fig. 5 is represented a pair of exposed bare copper conductors, on open supports, as sociated with a pair of number 19 cable conductors in a combination or compound circuit. As but one mile of such cable circuit equals about 13 miles of such copper circuit, three miles of cable pair would be the'transmission equivalent of about 40 miles of the number 12 bare copper exposed Wire circuit. Hence, the unit spacing distance for the number 12 wire would be approximately 40 miles when not modified by extraneous conditions. As the extraneous disturbances from parallel conductor electrostatic and magnetic effects from open wire construction are so variable along the average route of a long line, and as the spacing distance is so great, compared with the loading system, for a number 12 copper exposed conductor, and relatively greater for number 8 copper exposed wire circuits, and considering further the fact that frequently good stations for installing and facilitating the inspection of the coils and their protective equipment are available along the route of a line, and as closer spacing or the coils will not be materially more expensive but of some benefit, the spacing distance may be somewhat flexible and range from 35 to 45 miles for number 12 wire for the Whole section, the coils to be applied in half section lengths, or approximately, in this instance, twenty miles apart. It will be advisable when varying the spacing to adjust the distances to the conditions mentioned, and to have the sections graduated, so that very great differences and consequent unequal actions on the coils or windings may be avoided. The relative undisturbed circuit spacing distance for number 8 open wires approximates 90 miles, as, for trans-' mission, one mile of number 19 cable loop equals 30 miles of number 8 open wire circuit, but by reason of the modifying circumstances stated, the unit distance may be correspondingly flexible and vary from 80 to 95 miles, in which casethe coils should be spaced approximately 45 miles apart. Also, as to telephonic service, it may be stated thatabout thirty-five miles of standard No. 19 cable is the ordinary maximum distance for good transmission, (although experimentally greater lengths of such cable have been used), and while I prefer, for very long distances and to secure maximum efficiency, to space the resistance vents approximately for such cable at a mile and a half apart, yet beneficial results may be had by spacing them at greater distances apart so long as the spacing does not exceed approximately thirty-five miles of such cable.

To avoid any reflecting action of the waves in their change or transmission from one class of conductor to another, or from a line of one character to a line of another, as from a cable conductor to. an open wireconductor, it will be advantageous to locate the first coils from each end of such conductors, at about half the selected unit distance, as is clearly illustrated in Fig. 5. This will compensate in the coils for any differences in the effect of the electrostatic currents from the two first half sections of the two types of conductors.

An important incidental advantage, as referred to above, in the use of my system'ot coils for exhausting the electrostatic reactive currents set up by the original waves, is the corresponding dissipation of the currents induced along the circuit into the rectified circuit, which induced currents,- whether of electrostatic or electro-magnetic characteristic, flow in the rectified circuit in parallel in the two legs of a metallic circuit, and the coils are correspondingly permeable for their conduction to the ground connection. The parallel flow, in the two conductors,- of the static induced currents is in reverse directions towards the coils from the middle of. each rectifying section, provided the exposure is equal throughout the section, and the flow of the electro-magnetic induced currents is in one direction in both conductors 'in the section if the exposure is uniform and from the same source. It will thus be clear that all the electrostatic and also all the undesirable induced electro-magnetic currents, all parasitic iircliai'actel', are made to escape, or be deflected from the circuit, through the coils for'the sections wherein they are set up, and in a manner to avoid their having a suificient duration of time or extent of circuit flow to oppose the initially transmitted currents.

In the application of the coils to a circuit with a ground return, such as a' submarine cable might be, as illustrated in Fig. (5, the two conductor arrangement shown is desirable and efiicient, and the coil condi-,

tions may be as already explained but. preferably they should be varied in position by reason of the strictly parellel flow of the reactive electrostatic currents set up in the grounded circuit, by starting the spacing in full half section units from the ends, and especially if the conductor is not in a circuit with another of different electrical proportions, as illustrated at A and B in said view, where the middle taps to the terminal coils are first connected through terminal apparatus-T, T &' i.', and then to ground.

The coils in this arrangement should be of high resistance and with considerable inductance to prevent a free flow of the initial currents to ground. In this arrangement of a circuit the two legs are utilized as an independent metallic circuit, and the apparatus at each end of the metallic circuit, or at way stations, may be associated with the circuit conductively or inductively, but, as

illustrated, is conductively associated at A and B.

In Figs. 5 and 6 the conductors are shown in transposed relationship for convenience in drawing and for clearness in illustration.

A method of utilizing my coil system with a single grounded conductor is illustrated in Fig, 7. In this view the line terminals 6 and e of the coils are both connected to the one conductor 2, but the connections are separated by an inductance coil I having an inductance proportion just sufficient to create a lag in the initial currents of a quarter phase, to permit the proper actionof the compound coil 4 to the initial currents. That is, to permit or to cause the winding of the coils 4* next the then transmitting station, to be impermeable to the initial currents, as has been explained in the other association. Such action would not ensue if the coils I were not present in the line circuit, when both windings would accept the initial currents equally and opposingly. One effect in this instance is the use of the coils as light loading coils or inductance factors to neutralize such proportion of the electrostatic reactive currents as may purposely, or otherwise, be left in the circuit, by the coils 49- being made of greater relative retarding value to the electrostatic effects, to compensate for the requirements due to the presence of the coils I. In this instance the electrostaticrtaactivc currents are in part neutralized by the load or phase displacing coils I, and in part permitted to escape through the coils 4 and any induced electrostatic or electro-magnetic currents are made to escape through coils 4 The coils I and the two windings of coils 4 are, if considered alone with reference to the currents set up by the coils I, in series relation and thus the inductance of coils 4 will force the currents of the coils I to act in the line mainly. As the coils 4 are not in the. circuit but connected thereto in bridged relation only and to ground, the coils thus being in parallel relation to each other along the circuit, they may have as large an ohmic and reactance Value to the initial currents as to practically be impermeable thereto. So constituted, they will have no considerable shunting effect upon the transmission. To secure this condition the coils 4: should be constructed with sufficiently large laminated cores and with the magnetic circuit closed, and (depending upon the use and size of wire employed, and whether intended for cable or for outside use) should have an ohmic resistance of from 50 to 500 ohms for each winding, proportioned to or dependent on the length and type of the circuit. The windings should be wound on the core together or arranged in outer and inner halves for each winding, and wound over each other to secure a nicely balanced inductance effect,

as illustratedin Fig. 8. It is advantageous to have the windings associated with each other over the same section of the core, as if separated, the reluctance created by the core effect of each coil by its independent act-ion forsuch' frequencies would tend to prevent the non-inductance efi'ect necessary for the exhausting of the -.electrostatic currents when flowing through the two w ind-' ings of the coils in parallel. V

The inductance coil I, illustrated in Fig. 9, for use in the line circuit. as shown in Fig. 7, should be formed also with a highly permeable soft iron core and having a closed magnetic circuit, and the Winding Of.Sl1ltable gage wire for the character of service or use, and the coil should have a resistance and an inductance value properly proportioned to the electrostatic reaction of the circuit in which it is placed for service, it being understood, as stated above, that the coils 4 must be altered to permit the cir cuit to have some electrostatic reaction to which the coils I must be adjusted as for semi-loading conditions. I V

For use in exposed locations these coils, both the 4 and the I coils, should be properly housed or protected from the weather and also specially protected from lightning, high potential currents, and mechanical inur Iii Fig. 10, is shown a desirable form of protection from lightning discharges, high potential currents, &c., suitable for open wire construction, and there is an associated device in an inductance spiral to more effectually guard the coils from the destructive effects of lightning. Condensers D are placed between each winding of coil i and the ground, and in such manner as to break the continuity of the windings to direct currents. These condensers are for service in testing and measuring the circuits in connection with their maintenance, and if of proper dimensions or.- capacity would be useful also for composite circuit service overthe same circuit conductors. The protectors may be of the usual standard character for protection by jump. arresters- J J and by fusesF F and should be placed outside the coils next the lineconnections. The inductance spirals S, Sshouldbe connected to the circuit between the inductance coil and the line conductors.

In certain instances the coils 4*, Fig. 4,

may be arranged to serve as line drops or ringers, as signaling devices, at stations along the circuit where their location would agree .or correspond with their sectional spacing.

It will of course be obvious that certain modifications in the spacing of the coils, and their arrangement with relation to the line circuits, may be resorted to without departing from the essence and scope of my invention as herein explained. And it is plain also, that the coils 4", while more advantageous and somewhat preferred to or dinary resistances by reason of their an mented resistance property (due to their inductance) may be replaced by simple ohmic resistances of sufficient value to maintain the relative high and low. resistance paths to the initial currents, and to the electro-static reaction currents respectively.

\Vhat I, claimand desire to secure by Let ters Patent is:

1. The combination with a transmission circuit, of a plurality of composite electromagnetic coils connecting the circuit in multiple with the ground at intervals substantially equal to half a maximum length of such circuit capable of good transmission without such a coil applied to it.

.2. The combination with a transmission circuit, of a plurality of composite electromagnetic coilsconnecting the circuit in multiple with the ground at predetermined intervals along the circuit, said intervals being substantially uniform in length, and not exceeding in length, a length exemplified by a transmission equivalent of 35 miles of standard No. 19 cable circuit, with a telephonic speech frequency, according to the type of circuit and Wave frequency, substantially as set forth.

The combination with a transmission circuit, of a plurality of composite electromagnetic coils connecting the circuit in multiple with the ground at intervals, said intervals being of a length equal to substantially half the length of a section of such a circuit capable of good transmission after a coil is applied to it. 1

4. In an electrical wave conductor sys em, the combination with a wave. conductor circuit consisting of a wire conductor and a plurality of resistances distributed and connected throughout the length of the circuit at periodically recurring points, which for transmission are determined by and limited to a thirty-fivemile circuit of standard No. 19 cable, or its transmission equivalent for telephonic speech or higher frequency.

5. The method of reducing attenuation and distortion ofelectrical waves in a metallic circuit, consisting informing rectifying or exhausting sections along the circuit and deflecting the electrostatic currents set up in the sections to ground along the circuit by or through composite coils distributed along. the circuit at approximately uniformly periodically-recurrln points which points are within ood or on istorted transmission distance 0 each otheras specified.

6. The method of facilitating electrical wave transmission in a Wire circuit, consisting in setting up electro-magnetic waves in the circuit, and-relieving the circuit of the opposing electro-static' currents set up by the wave transmission by deflecting to the ground said electro-static currents in a regulated and predetermined manner through vents disposed at regular intervals throughout the entire length of the circuit limited substantially as set forth,

7 In the transmission of electrical waves in wires, the method of eliminating the opposing electrostatic reaction, consisting of distributing electro-magnetic coils connecting the line with the ground at predetermined points along the circuit, with sectional or local'flows oi the static currents to waves would be ordinarily transmitted in.

ground which points of connection or flows to ground are within a distance of each other insuflicient to cause individually any appreciable distortion of the waves.

8. The method of extending the range of transmission in a wave conductor, consisting in dividing the line into relieving sections, the sections being proportioned or having dimensions, so that the reactive static currents set up within them by the transmitted currents are less than enough to cause appreciable attenuation or distortion, the sections being defined by coils having two parallel windings presented to the line electrostatic currents, and said coils being placed between the line and the ground in parallel relation.

9. The method of wave transmission in a metallic wire circuit for the reduction of distortion and attenuation, consisting in establishing sections or local divisions of the circuit, in which sections electrostatic reacting currents opposing the initial currents are set up, and bridging the circuit with composite 1nductance-nonlnductance coils, each having a connection to ground to conduct away from the local divisions the reacting currents, and the spacing distance between coils being half the apportioned distance, over which the undistorted form.

10. In a wave transmission system, the method of relieving wire circuits'of electrostatic reaction currents produced by the original transmission currents, consisting in producing governable plural leaks or static vents at various points directly to ground throughout the length of the circuit, each within good transmlssion lengths of the circuit, substantially as set forth, for dissipating said electro-static reaction currents, said leaks being adapted'to prevent the flow or escape of the original wave currents from the normal circuit and .facilitate their transmission over such circuit, substantially as specified.

11. The method of transmitting electrical waves in a wire circuit, consisting in impressing waves on the circuit that produce reacting opposing electro-static currents, and then deflecting said opposing currents from the circuit to ground at regularly disposed.

points along the circuit, said deflections being sufficiently near together in their consecutive order to prevent distortion of the gages between them, substantially as speci- 12. In an electrical wave transmitting system, the combination with a metallic circuit extending between transmitting and receiving stations, of electro-magnetic coils bridging said circuit and connecting at their centers said circuit with the ground at predetermined successive points in the circuit, whereby rehevmg or dlsslpat ng means are formed by sald electro-magnetlc COll connec:

tions for the local flow and discharge of electro-static reactive currents set up by the original electric waves, the maximum length of circuit between the relieving means being determined by the type of circuit and the frequency of wave impressed thereon, and being as thirty five miles is to standard number 19 cable for the higher speech frequency, substantially as set forth.

13. A circuit for electrical wave transmission formed of a pair of wires between transmitting and receiving stations, and means associated with said circuit at intervals throughout its length for creating local current flows for the discharge to ground of the electro-static reacting currents set up by the transmitting currents, said intervals between successive discharging means being less, proportionately as to type of circuit and impressedfrequency than the distance for good or maintained characteristic wave that thirty five miles of standard number 19 cable bears to speech wave transmission, substantially as specified.

1 -A metallic circuit for electrical wave transmission and means associated with said circuit at intervals within undistorted transmission lengths of said circuit for connecting the circuit to ground, saidmeans adapted to prevent the dissipation of the original currents and effecting the dissipation of the counter-electrostatic currents set up by the wave transmission, 1

15. In a metallic circuit for electrical wave transmission, arbitrary sectional local circuits for the flow of electrostatic currents, setiIp by the wave transmission, combined with composite coils forming or defining said local sections, which sections are of'lengths approximately equal and of a length insuflicient to create perceptible distortion, said coils having a cooperative winding, divided and tapped out at their centers, the taps being connected to ground and the two ends of each coil being connected to the respective sides of the line and adapted to be inductive to the main current flow and non-inductive electric energy, the combination of electromagnetic coils associated with said circuit in regulated distances to create local discharge circuits for static currents, a ground connection to the middle tap of each coil, condensers interposed between the line-wires on each side and the ground, to conductive'ly separate the line-wiresat the coils, means within the coils for opposing currents havin a general flow and means within-"the coils or attracting or discharging currents haying merely a local or sectional flow. I

17-. -A multiple circuit for electrical transmission, consisting of a'rnetallic loop form ing one circuit, and a grounded circuit consisting of said loop and the earth, electromagnetic coils brid 'ng said metallic circuit at intervals, tween which transmission is not appreciably distorted, said coils having an earth connection at their centers and be' wound to oppose currents having a genera flow in the metallic circuit and to be non-opposing to currents having va local flow, whereby the initial currents are transmitted without retardation from electrostatic reacting currents created by such initial currents and said electrostatic currents are deflected from the circuit.

18. In a wave transmission system, the

combination with transmitting and receiving telephones connected by means of a wire circuit, of a resistance or lurality of resistances connected therewit to serve as an electrostatic vent, said resistance or resistances being brid ed between the circuit and the ground and isposed or spaced with reference to the length of the circuit to provide at least one such resistance connection between the circuit and the ground for such. portion or section length of circuit over which direct wave transmission would ordi-,

narily be eflicient between telephones without such resistance or resistances, that is a length substantially equivalent, relatively, to thirty five miles of standard number 19 cable, substantially as'specified.

NATHANIEL G. WARTH. Witnesses:

Amen B. Coon, BENJAMIN FINGKEL. 

